Danger: earthquake superhighways

Supershear earthquakes, as this New Scientist feature explains, are the seismic equivalent of a sonic boom.

In these potentially very destructive quakes the rupture travels so fast that it overtakes its own shock waves.

The article highlights the work of David Robinson and Shamita Das from Oxford University's Department of Earth Sciences who are trying to predict where these super-fast quakes are likely to strike next.

They compared past supershears looking for similarities and then looked for faults with the same characteristics: land-based faults that don't deviate by more than 5 degrees over a distance of 100 kms.

What they found were 26 sections on 11 different fault systems around the world that the researchers dubbed 'earthquake superhighways'.

What's especially worrying is that seven sections of superhighway run through highly populated areas - including along the San Andreas Fault under San Francisco and near Rangoon and Mandalay in Burma - with millions of people potentially in danger. 'The density of population in some areas of Asia we looked at is incredibly high. That really surprised me,' David told NS's Richard Fisher.

But as the article explains we just don't know enough about supershear earthquakes yet to advise engineers and planners what to do about them.

We just have to hope that the next one strikes in some remote and uninhabited area giving scientists vital data about these potentially devastating quakes.